The limitations of the Haber–Bosch reaction, particularly high-temperature operation, have ignited new interests in low-temperature ammonia-synthesis scenarios. Ambient N2 electroreduction is a compelling alternative but is impeded by a low ammonia production rate (mostly <10 mmol gcat –1 h–1), a small partial current density (<1 mA cm–2), and a high-selectivity hydrogen-evolving side reaction. Herein, we report that room-temperature nitrate electroreduction catalyzed by strained ruthenium nanoclusters generates ammonia at a higher rate (5.56 mol gcat –1 h–1) than the Haber–Bosch process. The primary contributor to such performance is hydrogen radicals, which are generated by suppressing hydrogen–hydrogen dimerization during water splitting enabled by the tensile lattice strains. The radicals expedite nitrate-to-ammonia conversion by hydrogenating intermediates of the rate-limiting steps at lower kinetic barriers. The strained nanostructures can maintain nearly 100% ammonia-evolving selectivity at >120 mA cm–2 current densities for 100 h due to the robust subsurface Ru–O coordination. These findings highlight the potential of nitrate electroreduction in real-world, low-temperature ammonia synthesis.

Interfacial polarization is reported as a brand new, efficient, and generalizable strategy to accelerate electrocatalytic reduction of N 2 to ammonia. The polarization is established by using an electric field to polarize N 2 . The electric field is triggered by protrusion-like single atoms anchored on MoS 2 . The interfacial polarization accelerates electron transfer from single atoms to N 2 and thus promotes N 2 reduction. As a result, ammonia synthesis in an electrochemical flow cell proceeds at a high rate of 36.1 G 3.6 mmol g À1 h À1 .

A low-cost nanoscale zinc catalyst, prepared by a facile electrochemical strategy, exhibits high activity toward electrochemical reduction of CO2 to CO with up to 93% Faraday efficiency in aqueous NaCl solution.

No abstract

No abstract